This invention relates generally to a machine for harvesting crops in a field and, more particularly, to a flexible crop curtain for directing crop movement into a rotary cutting header for harvesting tall, seed-bearing specialty crops.
In modern crop harvesting machines, it is desirable to optimize cutting headers for specific crops in order to maximize harvesting efficiency. Such optimized headers are typically based on existing header designs with specific-purpose modifications incorporated to alter finite portions of the crop flow into or within the header to suit the specific crop being harvested. This approach helps control production costs of the equipment and extends the life cycle of a basic header design.
One specific application involves harvesting of grass seed or other specialty crops having seeds on a stem which must be cut and dried in a windrow before threshing. Care must be taken when working with such crops to minimize disturbances to the crop material during the cutting and windrowing operation which can dislodge the seeds from the stem, especially when a rotary disc cutterbar is used.
Use of rotary cutterbar headers is well-known in the crop harvesting field and is favored due to higher ground speed capability compared to conventional sicklebar cutters. U.S. Pat. No. 5,784,866 granted to Campbell et al. on Jul. 28, 1998 shows a typical rotary crop severing header of this type. Rotary cutterbar headers are generally characterized by a forward opening that is short (on the order of 18 inches) and usually features a protective curtain to prevent debris struck by the rotary cutters from being ejected from the header. While such a short forward opening is not problematic in normal harvesting operations in which crop height may not significantly exceed the top of the forward opening, some grasses may be up to six feet tall at harvest. Lacking a reel or other apparatus to properly position the crop entering the header, a rotary disc cutterbar header moving through the tall grass initially causes the stem to be bent rearwardly followed by a forward whipping motion of the seed head as the top of the header moves over the base of the stem. This whip lash effect leads to loss of seed and is undesirable in a specialty crop header.
It would be desirable to provide an apparatus for managing the position of tall, seed-bearing crop as the crop enters a specialty crop header which reduces the loss of seed from the crop while efficiently positioning the crop for severing by a rotary disc cutterbar that overcomes the above problems and limitations. Still more desirable would be an apparatus that for managing entry of tall crops into a rotary disc cutterbar header that may be repositioned when not in use to avoid obstructing forward visibility from the machine.